My car sits for three weeks at a time with no issue. The manual specifies no more than .06 amp (60 mA) but you measure this by the exact procedure:

1) Disconnect battery ground cable
2) Insert an ammeter/DVM inline
3) With doors and trunk closed and key off and removed from the ignition, wait at least 3 minutes. (This allows the security system and other 'stuff' to get to it's "resting" state, looking at the meter too quickly will make you think you have a problem you do not really have)
4) Observe the meter - ANYTHING over 60mA is a PROBLEM.


My "gut" feeling is that your battery is on it's way out. The spoiler acting up is a good sign of either a bad battery, weak/flaky alternator or battery/ground cable in poor shape.